Operating System Not Found

The operating system not found error message is
one commonly seen by techs and non-technical people alike. If you run
into one, it may not be a problem at all. Here's an example:

If you're installing a new operating system to a hard drive or partition,
or have just installed a new motherboard, chances are that you have just experienced a minor OS error.
Most of the occurrences of the operating system not found error
occur during these processes. In many cases, this is simply BIOS related,
and can be changed very quickly (and remedied) during the Boot process.
There are a wide variety of occurrences of this error, so if you have
recently been "tinkering" or have installed a new operating
system, take heart, there are many computer forums on the subject which
may be able to point you to an answer.

Another reason why you may get an operating system not found message is due to a damaged or incorrectly formatted partition. If your computer can't read the partition, then all data stored within that partition cannot be found. This includes your operating system. To solve the problem, you may need to look into data recovery software.

There are instances, however, when the operating system not found error
occurs because of file system error, or worse, hard disk drive failure.
If this is the case, you may require professional hard disk drive recovery,
especially if you were not changing the system details recently, and were
just working as normal

When To Suspect Hard Disk Drive Failure

Certainly, there is an explanation for everything, and
the operating system not found error can be explained very easily.
First, check your floppy disk drive. Is there a disk in it? In cases where
this occurs, simply removing the floppy disk will likely solve your problem.
Your computer may have been looking for an operating system on the floppy,
and as a result, you were handed an error message. Removing the floppy
disk should fix your issue.

If there is no floppy disk in your drive, it may be time to check the
boot sequence. You can do this in your BIOS. First of all, does your hard
drive get detected as the primary hard drive? If it does not, your hard
drive may have in fact failed. If it does, move to the Boot Sequence section
of the BIOS. If your hard drive does not show up within the first three
boot devices, you probably have a problem. Adjust your BIOS accordingly.

Can't Find Hard Disk Drive Either

If you've done these preliminary checks, and are still receiving the
operating system not found error, you could be facing hard disk
drive failure. If this is the case, remember : DO NOT PANIC. 99 times
out of 100, your hard drive's data can be recovered by a professional
firm. So rest easy. Then try this test if you have another computer system
available.

First, disconnect your hard disk drive from your system, and connect
it to a system you know works as the slave drive.

Second, boot up the system and go into Windows explorer. If you
can see the drive, you may not have a problem at all, or have one which
can be fixed with simple data recovery software tools (Do a search on
Google for data recovery software tools for a selection).

If, on the other hand, you cannot see your drive, you may want
to consult a professional hard disk drive recovery shop like Hard Disk
Recovery Services.